Defect Code 20

*D* Defect code memory: 20 Brake light test switch

Possible cause:
Failure of brake light test switch; wire from BC to brake light test switch defective.

When brake light test switch (or line) is defective, the BC can no longer monitor the fuse and brake light switch.

Troubleshooting:
Check brake light test switch and renew if necessary. If switch OK., check wire from black BC connector Pin 1 to brake light test switch and repair as required.